Hydraulic clutch and power transmission



NOV. 19, 1935. AxE, E 2,021,182

HYDRAULI C CLUTCH AND POWER TRANSMISSION Filed 'April 26, 1933 3Sheets-Sheet 1 II I III IIIA A. E HEDLUND HYDRAULIC CLUTCH AND POWERTRANSMISSION Nov. 19, 1935.

5 Sheets-Sheet 2 Filed April 26, 1933 Nov. 19, 1935.

HYDRAULIC CLUTCH AND POWER TRANSMISSION I Filed April 26, 1935 A, E.HEDLUND 2,021,182 I 5 Sheets-Sheet 5 I Patented Nov. 19, 1935 HYDRAULIComrrcn mm rowan TRANSMISSION Axel E. Hedlund, Everett, Wash. ApplicationApril 26, 1933, Serial No. 668,021 4 Claims. (Cl. 19260) My inventionrelates specifically to hydraulic clutches in engines of the automotivetype, altho my clutch has other uses.

The particular type of' hydraulic clutch to 5 which I refer comprises ahollow fly wheel carried by the driving shaft,-within the chamber ofwhich fly wheel are provided a series of hydraulically controlledconnections between said fly wheel and the crank pin of the drivenshaft. Said connections consist of a series of hydraulic cylindersradial with the center of rotation of the fly wheel. These cylindershave ports located adjacent the interior periphery of the fly wheel.

In said cylinders reciprocate pistons, which are connected to thecrankpin of the driven shaft, and the ports of said cylinders arecontrolledby manually operated valves;

, The operation of said prior type of clutch in brief is as follows:

The fly wheel is partly filled with a liquid, preferably oil, which dueto centrifugal force when the fly wheel is in rotation forms a circularbody on the interior periphery of the fly wheels cham-.

her. The oil will then cover and tend to pass in and out of the ports ofthe cylinders. Since the pistons are connected to the crank pin of thedriven shaft, they will be reciprocated while said ports are open; butwhenthe valves controlling said cylinders are partly closed, and thepassage of the oil into and out of the cylinders is correspondinglyobstructed and retarded, then the driven shaft will be given somerotation from the fly wheel, because the flow of the oil thru said reereciprocation of the pistons within the cylin saidports are entirelyclosed, the resulting hydraulic pressure will prevent the pistons fromre clprocating at all, whereupon the rotation of the fly wheel will betransmitted in the nature of adirect drive to the driven shaft.

The objections which I have found, to the use of said hydraulic clutchis that free wheelin so essential to the modern motor of the'automotivetype-is'interfered with, due to the fixed character of. the crank pincarried by the driven shaft; for,since the crank pin is flxed saidpistons will continue to work even when the engine is idling; and suchcontinuous operation of the pistons imposes free wheeling. Besides, incase more or less heavy oil is used in the chamber of the fly wheel, lowatmospheric temperatures would tend .to

render the oil too viscous, and thus too slow--,to move in and out ofthe cylinders ports, and the pistons would exercise a drag on theengine.

rs. Then when I too much resistance and prevents The object of myinvention is to eliminate said objections.

I attain my object by making the crank pin of the driven shaft radiallymovable, so that it may be alined with the center, or axis of rotationof the driven shaft, thus placed in a neutral or inactive position, orprojected into, and held in eccentric, and thus active position, bymeans under the control of the operator of the engine.

The advantage of my invention is that while ience, as the crank pincontrol; and will refer go to the means for controlling the ports ofsaid cylinders, and thus the reciprocation of their pistons, as theclutch control.

My crank pin control is so contrived that when manually applied it willfunction to hold the crank pin in its eccentric, active posi tion. Andwhen my crank pin control is thrown into its active position, it willtransmitthe' full speed of rotation of the fly wheel to the drivenshaft. 'A further feature of my invention isthe cylinders of the flywheel clutch are provided withv safety valves, so as to prevent anyinjury due to overloading the motor. By my arrangement the resistingpressure exerted against the move- 'The above described features of myinvention are hereinafter fully described' with reference to theaccompanying drawings, in which:

Fig. 1 shows one entire embodiment of my-invention in the form of acentral; longitudinal vertical section of the thereby carried and'the'driven shaft;

Fig. la shows a section on the line ia-la of F18. 1;

project and 25' ment of the pistons may be limited, so that indissipatedso arranged as to. avoid excessive wear and tear.

driving shaft, the fly wheel v dismounted from the driving shaft andparts of the case of the fly wheel broken away so as to show theinterior hydraulic pump elements;

Fig. 3 shows a front elevation of the head of thedriven shaft with itssliding wrist pin;

Fig. 4 shows a top view of the head of the driven shaft partly in plansection;

Fig. 4a shows a plan section taken thru the ports 10, p2 of the head ofthe driven shaft; compare Figs. 3, 5 and 4;

Fig. 5 shows a section taken on the line 55 of Fig. 1 and Fig. 4; e

Fig. 6 shows a section on the line s-t of Fig. 1;

Fig. 7 shows a section on the line '|-'l of Fig. 1;

Fig. 8 shows a fragmentary sectional exterior view of the fly wheel asshown by Fig. 2, looking at the latter in the direction pointed by thearrow 8;

Fig. 9 shows a modification of my device; the wrist pin in this instancebeing eccentrically mounted on a rotatable disk, the disk being rotatedby a pinion;

Fig. 10 shows a sectional elevation of the front end of the embodimentof my invention as shown in Fig. 9, with parts broken away to disclosethe interior elements; and

Fig. 11 shows a section taken on the line ill-ii of Fig.9.

a is the crank or driving shaft of the motor. On it is mounted a hollowfly wheel b.

The fly wheel? clutch Within the chamber of the fly wheel are provided aseries of radially disposed hydraulic cylinders w, in which reciprocatepistons 11. Opposite pistons e, are connected by a bar it having acentrally located slotted head it, in which bears the radially movablecrank pin 0 of the driven shaft d.

Hence, when said crank pin is in its eccentric,

activeposition then the rotation of the fly wheel b will cause thepistons a, to be reciprocated, due

' to the resistance of the crank pin. But when the latter is in itsinoperative position, that is, alined with the center of rotation. ofthe driven shaft a, then the pistons will not be reciprocated.

Crank pin control The crank pin 0 is projected into its eccentric,active position by the hydraulic means provided in the chamberedextension d of the driven shaft ber d2 thru a check valve 1', into oilduct h, andv from thence into the pump cylinder 9!.

The pump 1 is moved in one direction by the expansion spring f2. Theextension e' of the hub of the fly wheel is provided "with an eccentricchamber e2 (see Fig. 1a) in which travels the wheel I of the pump 1..Hence, while the hub e of the fly wheel rotates about the driven shaftextension d,-theipump will be operated.

The ofl under pressure of the pump 1 flows from the pump cylinder g thrua check valve is into the oil duct i, and from thence thru the latterslateral branches J, i2 (see Fig. 4a) into the lower end ports of thecylinders l, l', in which reciprocate pistons m; m. These pistons carrya slide n having the crank pin 0.

The cylinders l. l are provided with return 5 ports p, p2 (see Fig. 4)which connect'with the oil duct 1), leading back into the chamber .112.

A spring controlled, manually operated valve s controls the applicationof hydraulic pressure by the circulation of the oil in chamber d2 whenthe pump 1 is operated. The valve s is operated by a collar t,longitudinally slidable on the driven shaft extension d by means (notshown) under the control of the driver.

When the valve 8 is opened the operation of 5 the pump f forces the oilthru check valve is into duct 7, and it will flow from the latter toduct q and thru the valve port r of the valve 3 back into the chamberd2, thus making a short circuit, withoutacting upon the pistons m, m.But when the valve 3 is closed said return flow thru the duct q beingstopped, the oil flowing thru duct 1' is forced thru the ports 7", 1'2into the cylinders l, l and lifts the pistons m, m until the returnports p, 122 are uncovered.

The further operation of the pump 1 will then cause the circulation ofthe oil thru ports :i', i2 and 12, p2 of the cylinders l, l' and thechamber 112, but under continued pressure holding the pistons m, m intheir raised position.

When the slide n, with its crank pin 0, is free to slide in the head d3of the driven shaft, the pull of the pistons of the hydraulic cylindersof the fly wheel clutch will place the crank pin 0 in alinement with thecenter of rotation of the driven shaft, thus in the inactive position.

The clutch control The case of the fly wheel b is partially filled withoil, and the centrifugal force engendered by 44 the rotation of the flywheel, will cause the oil to form itself'intoan annularbody against theinterior periphery of the fly wheel chamber.

Rotary valves :1: having ports in" control the ports w of the hydrauliccylinders w. The rotary 45 valves a: are provided with lateral, slottedarms :02, in which bear pins 1/, carried by arms of the collar z, faston the shank of the reciprocable rod i having a head 3 on which bears aspring 2. On the hub e of the fly wheel is slidably mounted a collar d,which is controlled by the operator by suitable means readilyunderstood, therefore not shown.

During the rotation of the fly wheel the ports to of the hydrauliccylinders w will be covered by said body of oil within the fly wheel;but, of course, so long as the valves :2: remain closed, the pistons 11,will not be reciprocatd.

By moving the collar 4 to the left against the the head 3 of the rod I,the collar .2 is so moved. as to cause its pins 11, y to rock the valves:c, and thus close the ports w of the hydraulic cylinders. partially orentirely. Y

The hub e of the fly wheel b is mounted by roller bearings on the drivenshaft extension (1 as shown in Fig. 1.

In order to prevent overloading of the motor, and thus imposingexcessive strain on the operative connections between the fly wheel andthe driven shaft, 1 provide the hydraulic cylinders it with safetyvalvesl, thru which excessive pressure is relieved. Each of these safetyvalves consists of a nipple 5 opening into the hydraulic cylinder w, andconnected with the interior of the passage 9 of the'fly wheel I) (seeFigs. 1 and 9).

The inlet thru the nipple 5 is controlled by a valve element 1 composedof a disc having a central hole, and a ball normally seated on and clos-1 ing said hole. The ball is held seated on said disk by spring 6; andthe said disc is normally held in closed position by a spring 8, thusnormally preventing the passage of pressure from the cylinder to intothe chamber of the fly wheel. The resistance of the valve 1 to suchpressure is adjustable by the adjustment of the tension of the spring 8by the cap 8a. When the pressure in the cylinder w is greater than thatof the resistance of said spring 8, it is relieved by passing from thecylinder back into the chamber of the'fly wheel. 7

A possible variation of the means for moving the crank pin of the drivenshaft into and out of its active position is illustrated in Figs. 9, 10and Referring to the latter figures: b designates the fly wheel, and eits hub; l0 designates the driven shaft, and Illa its extension on whichthe hub e of the fly wheel is rotatably mounted. To the head of thedriven shaft extension lCa is secured a plate provided with an annularrecess Ila, in which is rotatably mounted a gear l2 which carries thecrank shaft I3. The gear I2 'is provided with a pin |2a, the center ofwhich is eccentrically disposed with respect to the center of rotationof the driven shaft Ill, in order to move the crank pin l3 in an orbitwhich will place it in and out of its active position.

A pinion l4 rigid on a shaft 15' meshes with the gear I2. Aratchetpinion I6 is slidably" mounted on the shaft l5, and in one position isengaged with a pawl II' controlled by a spring I8.

K pawl I9 controlled by a spring |9a prevents the reverse rotation ofthe shaft IS. The ratchet pinion I6 is provided with a grooved collar|6a in which bears a lug 23 of a longitudinally slidble rod 20,connected to a sliding collar 2|, and is held in inactive position by aspring 24. The sliding collar 2| is assumed to be controlled by aquandrant and lever device, not shown; thus by moving the collar 2|against the spring 24, the ratchet pinion I6 is brought into engagementwith the pawl l1 and the pinion is rotated, thereby l rotating the gearI2, and placing the crank pin I3 in its active, eccentric position,until the sliding collar 2| is again released. l

The devices above described are to be understood as merely representingan embodiment of valves controlling said ports, operable to control thelatter and thus to restrain circulation of the fluid and therebyreciprocation of said pistons; a rotatable driven member provided with amovable crank-pin; each pair of pistons being centrally,operativelyconnected to said crank-pin;

said crank-pin in one position coinciding with the axes of rotation ofsaid fly wheel and said driven member, and in another position-beinglocated eccentrically with said axes, in its eccentric positioneffecting a power transmitting connection between said driving and saiddriven members, and in its other position permitting the pistons toremain at rest with no transmission of power from said driving member tosaid driven member; andmanually controlled hydraulic means for movingsaid crank-pin into and out of its said two positions.

2. The combination described by claim 1 with the manually controlledhydraulic means for moving the crank-pin including a chamber holdingliquid, a reciprocable element carrying said crank-pin operated bypressure in such chamber, and 'a pump element for producing suchpressure.

3. The combination described by claim 1 with the manually controlledmeans for moving the crank-pin including a chamber holding liquid, areciprocable element carrying said crank-pin operated by pressure insuch chamber, and a pump element for producing such pressure, said pumpelement operated by the rotation of said fly wheel.

4. The combination described by claim 1 with the manually controlledhydraulic means for moving the crank-pin including a hamber holdingliquid, a reciprocable element carrying said crank-pin operated bypressure in such chamber, a pump element for producing such pressure,such pump element operated by the rotation of said fly wheel, the liquidnormally circulating in said chamber, and manual means for arrestingsuch circulation and thus' causing pressure in said chamber.

' AXEL E. HEDLUND.

